1. Field of the Invention
The present invention relates to 1,1-bis(tert-butylperoxy)cyclododecane, a novel solid and stable compound, and its use as a crosslinking or curing agent.
2. Description of the Prior Art
It has been disclosed that bisperoxyketals can be used, together with dialkylperoxides, e.g., dicumyl peroxide, for crosslinking or curing natural rubber, synthetic rubber and ethylene homo-polymers and copolymers. Bisperoxyketals can lower the crosslinking temperature, since the thermal decomposition temperature of bisperoxyketals is lower than that of dialkyl peroxides.
U.S. Pat. No. 2,455,569 discloses an extensive use of bisperoxyketals and bisperoxyacetals. However, it does not make reference to their use as crosslinking catalysts.
German Pat. No. 945,187 discloses the use of 2,2-bis(tert-butylperoxy)butane and 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane as catalysts for a rubber vulcanizing process.
U.S. Pat. No. 3,296,184 discloses the combined use of 2,2-bis(tert-butylperoxy)butane, 1,1,7,7-tetra(tert-(butylperoxy)cyclododecane and sulfur for crosslinking olefin homo-polymers and copolymers.
British Pat. No. 1,044,010 discloses the use of 2,2-bis(4,4-di-tert-butylperoxy cyclohexyl)propane as a catalyst for crosslinking. This compound has about the same thermal decomposition rate as that of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane.
U.S. Pat. No. 3,433,825 discloses esters of 4,4-bis(tert-butylperoxy)pentanoic acid. These peroxides have a thermal decomposition rate slower than that of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, and therefore can be used without scorching or premature cure, according to the disclosure.
U.S. Pat. No. 3,686,102 discloses 2,2-bis(tert-butylperoxy)-4-methylpentane as a bisperoxyketal which can be used at a temperature between that for 1,1-bis(tert-butylperoxy)-3,3,5-trimethylhexane and that for n-butyl-4,4-bis(tert-butylperoxy)valerate. However, this compound has a relatively low molecular weight, and therefore is volatilized in a crosslinking process. Accordingly, only 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcycohexane and n-butyl-4,4-bis(tert-butylperoxy) valerate are sold in the market as crosslinking catalysts.
German Pat. Application No. 2,317,965 laid open to public inspection discloses bis(tert-octylperoxy)alkane. However, this compound is faster in thermal decomposition rate than tert-butyl derivatives, and therefore is not suitable for use as a crosslinking catalyst.